Field of the Invention
The disclosure generally relates to an antenna structure, and more particularly to an antenna structure with high gain characteristics.
Description of the Related Art
With the progress of mobile communication technology, portable electronic devices, such as portable computers, mobile phones, tablet computers, multimedia players, and other hybrid functional mobile devices, have become more common To satisfy consumer demand, portable electronic devices can usually perform wireless communication functions. Some functions cover a large wireless communication area; for example, mobile phones using 2G, 3G, and LTE (Long Term Evolution) systems and using frequency bands of 700 MHz, 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, 2100 MHz, 2300 MHz, and 2500 MHz. Some functions cover a small wireless communication area; for example, mobile phones using Wi-Fi, Bluetooth, and WiMAX (Worldwide Interoperability for Microwave Access) systems and using frequency bands of 2.4 GHz, 3.5 GHz, 5.2 GHz, and 5.8 GHz.
Antennas are indispensable elements in the wireless communication field. If the antenna gain of an antenna for signal reception or transmission is insufficient, the communication quality of the related mobile device will be degraded accordingly. Therefore, it is a critical challenge for antenna designers to design antenna elements with high gain characteristics.